The first of many Raleigh 20s I've owned; I bought this one used in the early '70s, and did many modifications to it over the years. In this photo, it was still fairly stock, except that I'd converted the 3-speed hub to 5-speeds, extended the seatpost, and installed Lyotard platform pedals and a Brooks B66 saddle.
For a while it had BMX tires on it, and I did quite a lot of off-road riding on this bike, before real mountain bikes became available. It used to really blow peoples minds to meet a cyclist out on a hiking trail in the woods...most people at the time assumed that such trails were impassible to bicycles.
Later in its life, it acquired aluminum rims, Cinelli handlebars and stem, a Campagnolo Nuovo Record crank set, Phil Wood bottom bracket, and other goodies.
One nifty use for such a bike is hitch-hiking. Back when I was a starving hippie, I once used this bike to visit friends on Cape Cod, during the winter off season. I hopped on the bike at my commune in Allston, (an outlying section of Boston) and rode in, perhaps 6-8 miles to the main north-south highway that runs through Boston, and up an on-ramp. I then folded the bike and stuck out my thumb.
A hitch-hiker with a crumpled up bike next to him looks less threatening than a normal hitch-hiker, and I got a ride almost immediately, all the way down to route 6, about 10 miles from my destination. There I was, on a dark November night, on a deserted 2-lane in Cape Cod, with nobody going by. If I'd been purely hitch-hiking, I'd've been S.O.L., but since I had my trusty Twenty, I just unfolded it, turned on my Elite headlight and had a pleasant ride to my friend's house.
Later, I lent this bike to one of my partners in the Bicycle Repair Collective (now the Broadway Bicycle School) so he could comfortably hitch back to his home in Minnesota at Christmas time. Worked for him, too!
In the early '80s, after I'd married and my daughter Tova was born, this bike acquired a baby seat. I chose this bike for baby seat use partly due to its sturdiness, partly due to the step-through frame, and partly because it was adjustable so that either Harriet or I could comfortably ride it.
Harriet used this bike for her 16 mile commute for quite a while...it was a bit of a "Q-ship" Harriet had a lot of fun blowing off posers on thousand-dollar bikes. When you're a poser with a thousand-dollar bike, and you pass a middle-aged woman on a small-wheel folding bike with a baby seat on it, there's precious little glory, (especially as the only chance these worthies had to pass her was while she was waiting for a red light to change.) On the other hand, once the light changes, and the middle-aged woman on a small-wheel-folder-with-a-baby-seat catches and passes you, you know you've really been passed!